The U.S. Federal Reserve System publishes data on family income based on its Survey of Consumer Finances. When the head of the household has a university degree, the mean pre-tax family income is $...

Q42

Extracted text: The U.S. Federal Reserve System publishes data on family income based on its Survey of Consumer Finances. When the head of the household has a university degree, the mean pre-tax family income is $ 85,400. Suppose that 70% of the pre-tax family incomes when the head of the household has a university degree are between $75,600 and $95,200 and that these incomes are normally distributed. What is the standard deviation of pre-tax family incomes when the head of the household has a university degree? (Round the value of z to 2 decimal places, e.g. 0.75. Round your answer to 2 decimal places, e.g. 125.75.)